Why doesn't the ringer volume also change the alert volumes (SMS, mail, calendar etc.)?! It seems a bit stupid that it only changes the volume of an actual incoming call ringer...I hope Apple sort this out in a future update.
I was thinking the other way as well to be honest - theres no way to lower the level of the alerts either, which would be handy for me late at night. Theyre just either on or off! And you cant forward SMS either! Hope Steve sorts these glaringly obvious omissions out soon! Still love my iPhone though